| 摘要 |
PURPOSE:To prevent a noisy alarm and malfunctioning by causing the onboard element of each vehicle to read and store installation position information without contact when each vehicle passes the position where a ground element is installed and to signal the other onboard element using radio waves, and causing the latter onboard element to compute the distance between the vehicles according to the signal and its own current position information and to issue an alarm. CONSTITUTION:Ground elements, 101, 102-10n, of e.g. electromagnetic induction communications type, are installed at predetermined intervals along a track 6, and data showing the installation site of each ground element are stored in the nonvolatile memory of each ground element. Each of maintenance vehicles 1a, 1b running on the track 6 is provided with a communications circuit for transceivers T, R to communicate with the ground elements by radio wave method and an onboard element 20 having an alarm that warns of collisions. When the maintenance vehicle 1b receives a signal from the onboard element 20 of the other maintenance vehicle 1a, for example, the distance to the maintenance vehicle 1a is computed, and an alarm is issued when the distance is not greater than a vehicle approach limit interval. As a result, the alarm is issued only with one of the maintenance vehicles 1a, 1b approaching the other, and is thus prevented from being continued. |
